/*  Starshatter OpenSource Distribution
    Copyright (c) 1997-2004, Destroyer Studios LLC.
    All Rights Reserved.

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    modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
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      may be used to endorse or promote products derived from this software
      without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.

    SUBSYSTEM:    Stars.exe
    FILE:         CampaignPlanStrategic.cpp
    AUTHOR:       John DiCamillo


    OVERVIEW
    ========
    CampaignPlanStrategic prioritizes targets and defensible
    allied forces as the first step in force tasking.
*/

#include "MemDebug.h"
#include "CampaignPlanStrategic.h"
#include "Campaign.h"
#include "Combatant.h"
#include "CombatGroup.h"
#include "CombatUnit.h"
#include "CombatZone.h"
#include "Random.h"

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ExecFrame()
{
    if (campaign && campaign->IsActive()) {
        if (Campaign::Stardate() - exec_time < 300)
        return;

        ListIter<CombatZone> zone = campaign->GetZones();
        while (++zone)
        zone->Clear();

        ListIter<Combatant>  iter = campaign->GetCombatants();
        while (++iter) {
            Combatant*     c     = iter.value();
            CombatGroup*   force = c->GetForce();

            force->CalcValue();

            PlaceGroup(force);
            ScoreCombatant(c);
            ScoreNeeds(c);

            force->ClearUnlockedZones();
            AssignZones(c);
            ResolveZoneMovement(force);
        }

        exec_time = Campaign::Stardate();
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::PlaceGroup(CombatGroup* g)
{
    if (!g)
    return;

    Text        rgn  = g->GetRegion();
    CombatZone* zone = campaign->GetZone(rgn);

    // if we couldn't find anything suitable,
    // just pick a zone at random:
    if (!zone && g->IsMovable()) {
        int nzones = campaign->GetZones().size();
        int n      = RandomIndex() % nzones;
        zone       = campaign->GetZones().at(n);

        Text assigned_rgn;
        if (!campaign->GetZone(rgn)) {
            assigned_rgn = *zone->GetRegions().at(0);
            g->AssignRegion(assigned_rgn);
        }
    }

    if (zone && !zone->HasGroup(g))
    zone->AddGroup(g);

    ListIter<CombatGroup> iter = g->GetComponents();
    while (++iter)
    PlaceGroup(iter.value());
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ScoreCombatant(Combatant* c)
{
    // prep lists:
    c->GetDefendList().clear();
    c->GetTargetList().clear();

    ScoreDefensible(c);

    ListIter<Combatant> iter = campaign->GetCombatants();
    while (++iter) {
        if (iter->GetIFF() > 0 && iter->GetIFF() != c->GetIFF())
        ScoreTargets(c, iter.value());
    }

    // sort lists:
    c->GetDefendList().sort();
    c->GetTargetList().sort();
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ScoreDefensible(Combatant* c)
{
    if (c->GetForce())
    ScoreDefend(c, c->GetForce());
}

void
CampaignPlanStrategic::ScoreDefend(Combatant* c, CombatGroup* g)
{
    if (!g || g->IsReserve())
    return;

    if (g->IsDefensible()) {
        g->SetPlanValue(g->Value());
        c->GetDefendList().append(g);

        CombatZone* zone  = campaign->GetZone(g->GetRegion());
        ZoneForce*  force = 0;

        if (zone)
        force = zone->FindForce(c->GetIFF());

        if (force)
        force->GetDefendList().append(g);
    }

    ListIter<CombatGroup> iter = g->GetComponents();
    while (++iter) {
        ScoreDefend(c, iter.value());
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ScoreTargets(Combatant* c, Combatant* t)
{
    if (t->GetForce())
    ScoreTarget(c, t->GetForce());
}

void
CampaignPlanStrategic::ScoreTarget(Combatant* c, CombatGroup* g)
{
    if (!g || g->IntelLevel() <= Intel::SECRET)
    return;

    if (g->IsTargetable()) {
        g->SetPlanValue(g->Value() * c->GetTargetStratFactor(g->Type()));
        c->GetTargetList().append(g);

        CombatZone* zone  = campaign->GetZone(g->GetRegion());
        ZoneForce*  force = 0;

        if (zone)
        force = zone->FindForce(c->GetIFF());

        if (force)
        force->GetTargetList().append(g);
    }

    ListIter<CombatGroup> iter = g->GetComponents();
    while (++iter) {
        ScoreTarget(c, iter.value());
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ScoreNeeds(Combatant* c)
{
    ListIter<CombatZone> zone = campaign->GetZones();
    while (++zone) {
        ZoneForce* force = zone->FindForce(c->GetIFF());

        // clear needs:
        force->SetNeed(CombatGroup::CARRIER_GROUP,      0);
        force->SetNeed(CombatGroup::BATTLE_GROUP,       0);
        force->SetNeed(CombatGroup::DESTROYER_SQUADRON, 0);
        force->SetNeed(CombatGroup::ATTACK_SQUADRON,    0);
        force->SetNeed(CombatGroup::FIGHTER_SQUADRON,   0);
        force->SetNeed(CombatGroup::INTERCEPT_SQUADRON,   0);

        // what defensive assets are needed in this zone?
        ListIter<CombatGroup> def = force->GetDefendList();
        while (++def) {
            int defender_type = *CombatGroup::PreferredDefender(def->Type());
            force->AddNeed(defender_type, def->Value());
        }

        // what offensive assets are needed in this zone?
        ListIter<CombatGroup> tgt = force->GetTargetList();
        while (++tgt) {
            int attacker_type = *CombatGroup::PreferredAttacker(tgt->Type());
            force->AddNeed(attacker_type, tgt->Value());
        }
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::BuildGroupList(CombatGroup* g, List<CombatGroup>& groups)
{
    if (!g || g->IsReserve())
    return;

    if (g->IsAssignable())
    groups.append(g);

    ListIter<CombatGroup> iter = g->GetComponents();
    while (++iter)
    BuildGroupList(iter.value(), groups);
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::AssignZones(Combatant* c)
{
    // find the list of assignable groups, in priority order:
    List<CombatGroup> groups;
    BuildGroupList(c->GetForce(), groups);
    groups.sort();

    // for each group, assign a zone:
    ListIter<CombatGroup> g_iter = groups;

    // first pass: fighter and attack squadrons assigned to star bases
    while (++g_iter) {
        CombatGroup* g     = g_iter.value();
        int          gtype = g->Type();

        if (gtype == CombatGroup::ATTACK_SQUADRON    ||
                gtype == CombatGroup::FIGHTER_SQUADRON   ||
                gtype == CombatGroup::INTERCEPT_SQUADRON) {
            CombatGroup* parent = g->GetParent();

            if (parent && parent->Type() == CombatGroup::WING)
            parent = parent->GetParent();

            if (!parent || parent->Type() == CombatGroup::CARRIER_GROUP)
            continue;

            // these groups are attached to fixed resources,
            // so they must be assigned to the parent's zone:
            CombatZone* parent_zone = campaign->GetZone(parent->GetRegion());

            if (parent_zone) {
                ZoneForce*  parent_force = parent_zone->FindForce(g->GetIFF());

                if (parent_force) {
                    g->SetAssignedZone(parent_zone);
                    parent_force->AddNeed(g->Type(), -(g->Value()));
                }
            }
        }
    }

    // second pass: carrier groups
    g_iter.reset();
    while (++g_iter) {
        CombatGroup* g     = g_iter.value();
        int          gtype = g->Type();

        if (gtype == CombatGroup::CARRIER_GROUP) {
            int         current_zone_need = 0;
            int         highest_zone_need = 0;
            CombatZone* highest_zone      = 0;
            ZoneForce*  highest_force     = 0;
            CombatZone* current_zone      = 0;
            ZoneForce*  current_force     = 0;

            List<CombatZone> possible_zones;

            if (g->IsZoneLocked()) {
                current_zone  = g->GetAssignedZone();
                current_force = current_zone->FindForce(g->GetIFF());
            }

            else {
                ListIter<CombatZone> z_iter = campaign->GetZones();
                while (++z_iter) {
                    CombatZone* zone  = z_iter.value();
                    ZoneForce*  force = zone->FindForce(g->GetIFF());
                    int         need  = force->GetNeed(CombatGroup::CARRIER_GROUP)     +
                    force->GetNeed(CombatGroup::ATTACK_SQUADRON)   +
                    force->GetNeed(CombatGroup::FIGHTER_SQUADRON)  +
                    force->GetNeed(CombatGroup::INTERCEPT_SQUADRON);

                    if (g->IsSystemLocked() && zone->System() != g->GetAssignedSystem())
                    continue;

                    possible_zones.append(zone);

                    if (zone->HasRegion(g->GetRegion())) {
                        current_zone_need = need;
                        current_zone      = zone;
                        current_force     = force;
                    }

                    if (need > highest_zone_need) {
                        highest_zone_need = need;
                        highest_zone      = zone;
                        highest_force     = force;
                    }
                }
            }

            CombatZone* assigned_zone  = current_zone;
            ZoneForce*  assigned_force = current_force;

            if (highest_zone_need > current_zone_need) {
                assigned_zone  = highest_zone;
                assigned_force = highest_force;
            }

            // if we couldn't find anything suitable,
            // just pick a zone at random:
            if (!assigned_zone) {
                if (possible_zones.isEmpty())
                possible_zones.append(campaign->GetZones());

                int nzones = possible_zones.size();
                int n      = RandomIndex() % nzones;

                assigned_zone  = possible_zones.at(n);
                assigned_force = assigned_zone->FindForce(g->GetIFF());
            }

            if (assigned_force && assigned_zone) {
                Text assigned_rgn;
                if (!campaign->GetZone(g->GetRegion())) {
                    assigned_rgn = *assigned_zone->GetRegions().at(0);
                    g->AssignRegion(assigned_rgn);
                }

                g->SetAssignedZone(assigned_zone);
                assigned_force->AddNeed(g->Type(), -(g->Value()));

                // also assign the carrier's wing and squadrons to the same zone:
                ListIter<CombatGroup> squadron = g->GetComponents();
                while (++squadron) {
                    squadron->SetAssignedZone(assigned_zone);
                    assigned_force->AddNeed(squadron->Type(), -(squadron->Value()));

                    if (squadron->Type() == CombatGroup::WING) {
                        ListIter<CombatGroup> s = squadron->GetComponents();
                        while (++s) {
                            s->SetAssignedZone(assigned_zone);
                            assigned_force->AddNeed(s->Type(), -(s->Value()));
                        }
                    }
                }
            }
        }
    }

    // third pass: everything else
    g_iter.reset();
    while (++g_iter) {
        CombatGroup* g     = g_iter.value();
        int          gtype = g->Type();

        if (gtype == CombatGroup::BATTLE_GROUP || gtype == CombatGroup::DESTROYER_SQUADRON) {
            int         current_zone_need = 0;
            int         highest_zone_need = 0;
            CombatZone* highest_zone      = 0;
            ZoneForce*  highest_force     = 0;
            CombatZone* current_zone      = 0;
            ZoneForce*  current_force     = 0;

            List<CombatZone> possible_zones;

            if (g->IsZoneLocked()) {
                current_zone  = g->GetAssignedZone();
                current_force = current_zone->FindForce(g->GetIFF());
            }

            else {
                ListIter<CombatZone> z_iter = campaign->GetZones();
                while (++z_iter) {
                    CombatZone* zone  = z_iter.value();
                    ZoneForce*  force = zone->FindForce(g->GetIFF());
                    int         need  = force->GetNeed(g->Type());

                    if (g->IsSystemLocked() && zone->System() != g->GetAssignedSystem())
                    continue;

                    possible_zones.append(zone);

                    // battle groups can do double-duty:
                    if (gtype == CombatGroup::BATTLE_GROUP)
                    need += force->GetNeed(CombatGroup::DESTROYER_SQUADRON);

                    if (zone->HasRegion(g->GetRegion())) {
                        current_zone_need = need;
                        current_zone      = zone;
                        current_force     = force;
                    }

                    if (need > highest_zone_need) {
                        highest_zone_need = need;
                        highest_zone      = zone;
                        highest_force     = force;
                    }
                }
            }

            if (highest_zone_need > current_zone_need) {
                g->SetAssignedZone(highest_zone);

                if (highest_force)
                highest_force->AddNeed(g->Type(), -(g->Value()));
            }
            else {
                if (!current_zone) {
                    if (possible_zones.isEmpty())
                    possible_zones.append(campaign->GetZones());

                    int nzones = possible_zones.size();
                    int n      = RandomIndex() % nzones;

                    current_zone  = possible_zones.at(n);
                    current_force = current_zone->FindForce(g->GetIFF());
                }

                g->SetAssignedZone(current_zone);

                if (current_force)
                current_force->AddNeed(g->Type(), -(g->Value()));

                Text assigned_rgn;
                if (!campaign->GetZone(g->GetRegion())) {
                    assigned_rgn = *current_zone->GetRegions().at(0);
                    g->AssignRegion(assigned_rgn);
                }
            }
        }
    }
}

// +--------------------------------------------------------------------+

void
CampaignPlanStrategic::ResolveZoneMovement(CombatGroup* g)
{
    CombatZone* zone = g->GetAssignedZone();
    bool        move = false;

    if (zone && !zone->HasRegion(g->GetRegion())) {
        move = true;
        CombatZone* old_zone = g->GetCurrentZone();
        if (old_zone)
        old_zone->RemoveGroup(g);
        zone->AddGroup(g);
    }

    ListIter<CombatGroup> comp = g->GetComponents();
    while (++comp)
    ResolveZoneMovement(comp.value());

    // assign region last, to allow components to
    // resolve their zones:
    if (zone && move)
    g->AssignRegion(*zone->GetRegions().at(0));
}
